$\frac{2}{5}(a-7)$ if $a=37$

Step 1 ：We are given the expression \(\frac{2}{5}(a-7)\) and the value of \(a\) as 37.

Step 2 ：We substitute the value of \(a\) into the expression, which gives us \(\frac{2}{5}(37-7)\).

Step 3 ：Simplify the expression inside the parentheses first, which gives us \(\frac{2}{5}(30)\).

Step 4 ：Finally, we multiply 2 by 30 and then divide by 5 to get the final result of 12.0.

Step 5 ：Final Answer: The result of the expression \(\frac{2}{5}(a-7)\) when \(a=37\) is \(\boxed{12.0}\).